Promotion of boron diffusion and gettering by employing thin Al2O3 layer as a reaction barrier.

Saved in:

Bibliographic Details
Title:	Promotion of boron diffusion and gettering by employing thin Al2O3 layer as a reaction barrier.
Authors:	Zhang, Zhen¹ (AUTHOR), Yang, Ning² (AUTHOR), Lu, Minglei¹ (AUTHOR), Yuan, Xiao¹ (AUTHOR), Ye, Xiaojun¹ (AUTHOR), Liu, Cui¹ (AUTHOR) liucui@ecust.edu.cn, Li, Hongbo¹ (AUTHOR) lihongbo@ecust.edu.cn
Source:	Journal of Materials Science: Materials in Electronics. Apr2021, Vol. 32 Issue 7, p8205-8212. 8p.
Subjects:	Gettering, Silicon oxide, Boron, Spin coating, Surface resistance, Refractive index, Boron steel, Aluminum oxide
Abstract:	The formation of a boron-rich layer (BRL) is a common phenomenon during the fabrication of boron (B) emitter due to different solubility of B in the silicon oxide layer and the silicon substrate. In our work, we employ alumina oxide (Al2O3) layers as reaction barriers to avoid the production of the silicon oxide layer and eliminate the BRL. The B diffusion in silicon becomes much more accessible that the diffusion concentration and depth are increased dramatically with the absence of BRL. The Al2O3 layer can also improve the uniformity of surface sheet resistance due to its hydrophilic, bringing superior quality of liquid boron source spin coating. We investigate the influence of Al2O3 with different thicknesses and refractive indexes on the B diffusion. The diffusion profiles of B in the silicon capped with Al2O3 become broader as the thicknesses and refractive indexes of Al2O3 increase. Besides, iron is employed as a model impurity to study the gettering effects during the B diffusion. The increase of the maximum B concentration and the total amount of B doping contribute to a superior gettering effect with the interstitial iron concentration decrease from 3.91e12 cm−3 to a minimal value of 1.65e11 cm−3, and the iron concentration even dropped to 7.24e10 cm−3 after attaching a second deposition. We analyze the mechanisms of gettering systematically during the B diffusion. The present work will help deepen the understanding of B doping and the fabrication of B emitter. [ABSTRACT FROM AUTHOR]
	Copyright of Journal of Materials Science: Materials in Electronics is the property of Springer Nature and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database:	Engineering Source

Description
Abstract:	The formation of a boron-rich layer (BRL) is a common phenomenon during the fabrication of boron (B) emitter due to different solubility of B in the silicon oxide layer and the silicon substrate. In our work, we employ alumina oxide (Al2O3) layers as reaction barriers to avoid the production of the silicon oxide layer and eliminate the BRL. The B diffusion in silicon becomes much more accessible that the diffusion concentration and depth are increased dramatically with the absence of BRL. The Al2O3 layer can also improve the uniformity of surface sheet resistance due to its hydrophilic, bringing superior quality of liquid boron source spin coating. We investigate the influence of Al2O3 with different thicknesses and refractive indexes on the B diffusion. The diffusion profiles of B in the silicon capped with Al2O3 become broader as the thicknesses and refractive indexes of Al2O3 increase. Besides, iron is employed as a model impurity to study the gettering effects during the B diffusion. The increase of the maximum B concentration and the total amount of B doping contribute to a superior gettering effect with the interstitial iron concentration decrease from 3.91e12 cm−3 to a minimal value of 1.65e11 cm−3, and the iron concentration even dropped to 7.24e10 cm−3 after attaching a second deposition. We analyze the mechanisms of gettering systematically during the B diffusion. The present work will help deepen the understanding of B doping and the fabrication of B emitter. [ABSTRACT FROM AUTHOR]
ISSN:	09574522
DOI:	10.1007/s10854-020-05124-6